i) Field of the Invention:
The present invention relates to inflammatory bowel disease (hereinafter referred to as IBD) preventive and curative agents containing a zinc L-carnosine salt or complex as an active ingredient, and a therapeutic method using the same.
ii) Description of the Background Art:
IBD is a term which means a disease with inflammation on an intestinal mucosa as a main place and inflammatory intestinal lesion due to a variety of causes, including ulcerative colitis from unknown causes, Crohn's disease and the like. Recently, these diseases have been increased, and therefore, designated as a research subject of the Special Disease Research Study Team of the Welfare Ministry in Japan. IBD is a chronic disease which repeats recrudescence and defervescence. The symptoms of IBD include mucous hemafecia or hemafecia repeated continuously or repeatedly, and an abnormal defecation such as diarrhea is observed.
As a cause of this disease, various theories such as infection theory, allergy theory, enzyme theory and the like have been presented. However, there is not established theory so far, and the cause is still unknown. In the meantime, autoimmunity theory is paid attention to since Broberger et al. reported that anticoli antibody was found from a patient's blood serum of this disease (see J. Exp. Med., Volume 115: pp. 13-26, 1962).
For the treatment of this disease, there has been employed two types of basic drugs which are salazosulfapyridine and adrenocortical steroid drugs. Further, an immunosuppressant such as azathioprine, metronidazole, antibiotics for preventing secondary infection are used, too. The salazosulfapyridine, a common preparation for the treatment of this disease is mostly decomposed into two metabolites of sulfapyridine and 5-aminosalicyclic acid by an action of enteric bacteria after oral dosage. It is considered that the salazosulfapyridine owes its effects to the 5-aminosalicyclic acid, and it seems that side-effects frequently observed are caused by the sulfapyridine of metabolite (see Khan et al., Lancet, p. 2892, 1977). Also, since the 5-aminosalicylic acid is unstable, and in effect, little amount of this substance reaches a colon when orally dosed, therapeutic effect is weak. As the side-effects of the salazosulfapyridine, nausea, vomiting, anorexia, exanthema, headache, hepatopathy, leukopenia, abnormal erythrocyte, proteinuria, diarrhea and the like are reported. Further, as the adrenocortical steroid drug, prednisolone is usually used in oral dosage, clysma, suppository, vein injection or the like with a strong side-effects such as gastric ulcer and caput femoris necrosis due to a long period of use.
Accordingly, a drug having strong IBD preventive and curative effects with reduced side-effects has been demanded.
Meanwhile, zinc L-carnosine salt is known to have a digestive ulcer therapeutic function (ssee Japanese Patent Application Laid-open (Kokai) No. 59-33270), preventive and therapeutic functions of hepatopathy (see Japanese Patent Application Laid-open (Kokai) No. 63-14728). However, it is neither taught or suggested that a zinc L-carnosine salt or complex has IBD preventive and curative functions, since the occurrence position, the occurrence mechanism and the therapeutic purpose are different.